Abstract
This study investigated a rapid start-up anaerobic ammonium oxidation (Anammox) process by inoculation with stored Anammox sludge and characterized the associated microbial communities. The Anammox process took only 43 days to start. A high nitrogen removal rate of 1.13 kg N m−3 d−1 and a nitrogen loading rate of 1.28 kg N m−3 d−1 were achieved. The ratio of ammonium removal to nitrite removal to nitrate production (1:1:0.2) was slightly lower than the theoretical value, which indicated nitrogen removal by denitrification in the reactor. Illumina high-throughput sequencing of sludge samples confirmed the co-existence of Anammox bacteria and denitrifying bacteria in the reactor and demonstrated that denitrifying bacteria play a role in nitrogen removal during the Anammox process. The dominant microbes in the reactor were Proteobacteria, Chlorobi, Chloroflexi, and Planctomycetes. However, only one species of Anammox bacteria, Candidatus jettenia, was identified and had an abundance of 4.92%. Our results illustrate the relationship between Anammox reactor performance and microbial community succession.
Highlights
Anaerobic ammonium oxidation (Anammox), which converts ammonia and nitrite to nitrogen gas under anaerobic conditions (Equation (1)) [1], was first discovered in a denitrifying fluidized bed reactor in the early 1990s [2]
The Anammox process was successfully initiated in 43 days in an using flow anaerobic sludge blanket (UASB) reactor
The Anammox process was successfully initiated in 43 days in an UASB reactor using stored Anammox sludge
Summary
Anaerobic ammonium oxidation (Anammox), which converts ammonia and nitrite to nitrogen gas under anaerobic conditions (Equation (1)) [1], was first discovered in a denitrifying fluidized bed reactor in the early 1990s [2]. The Anammox process has become a promising technology for the removal of nitrogen contaminants [3,4] and is a novel alternative to conventional biological processes for the treatment of wastewater. The process is a highly efficient and cost-effective technology for treating effluents with low C/N and high ammonia content as it allows for oxygen and organic carbon source retention and has an excellent nitrogen removal capacity [6]. Methods for decreasing or shortening the start-up period of Anammox reactors, including seeding with different types of sludge, altering reactor types, and using different types of bacterial carriers, have been the subject of increasing interest. Sludge with a high abundance of active Anammox bacteria should be used to seed Anammox reactors in order to accelerate the initiation of the Anammox process.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
